第三十二卷第四期 (期別128) (106年)

作者:

第三十二卷第四期 (期別128) (106年)

標題 化學植筋在低強度混凝土中剪力行為研究
作者 許家銘、鄭元良、蕭輔沛、廖文義、翁樸文、李台光、黃國倫
關鍵字 低強度混凝土、化學錨栓、植筋、剪力、補強
摘要 植筋工程常被用於結構物補強工程中，如翼牆及剪力牆補強等工法，藉由對既有結構體進行植筋，將補強結構體與既有結構體相連接，以期發展出良好的耐震行為。國家地震工程研究中心於校舍補強案例中，發現老舊校舍結構常有混凝土強度偏低的問題，其平均混凝土強度約為17 MPa，甚至有低至5 MPa 左右之案例，因此本研究探討低強度混凝土中植筋剪力行為，並探討現行ACI 混凝土設計規範之適用性。本研究在混凝土強度分別為5MPa、10 MPa 及15 MPa 之混凝土試體中，進行一系列的植筋單向剪力測試，試體共計有192 組，試驗控制參數包含植筋深度、邊距及混凝土強度。試驗結果與ACI 規範計算值相比較後，發現ACI 計算值在強度10MPa 和15MPa 之試體仍屬保守，但在5MPa 試體之試驗值則與計算值相當接近，故ACI 規範錨定計算公式應用於極低強度混凝土中可能會有不保守情況產生。此外，實驗發現有一種在低強度混凝土中的破壞模式屬鋼筋彎曲破壞，其強度介於邊距破壞與鋼筋剪斷之間，有別於ACI 規範中所考慮之邊距、撬破和鋼筋剪斷三種破壞模式。最後，本文以國內實際RC 剪力牆試驗與震害勘災結果，說明混凝土植筋界面剪力強度之重要性。
Title Study on the Shear Behavior of Chemical Anchors in the Low Strength Concrete
Author Jia-MingHsu, Yuan-Liang Zheng, Fu-Pei Hsiao, Wen-I Liao, Pu-Wen Weng, Tai-Kuang Lee, Guo-Luen Huang
Keywords low strength concrete, adhesiveanchors, post-installed rebars, shear, retrofit
Abstract In order to increase seismic capability of structural system, retrofit techniques are usually applied. Traditional RC retrofit methods include adding RC shear wall, wing wall and RC jacketing. In addition to connect new structural members to old structural members,adhesive anchors (post-installed rebars) are used. From the investigation results by National Center for Research on Earthquake Engineering (NCREE), it was found that concrete strength of old school buildings is very low due to poor construction quality. Therefore, the behavior of post-installed rebars in low strength concrete is very important. In this study, the concrete strength of specimens are 5MPa, 10MPa and 15MPa. According to the minimum edge distance and depth of ACI code, this study proposed a series of anchorage and shear test, a total of 192 specimens. Control parameters are the embedded depth of the rebar, the distance to edge, and concrete strength. The results of those experiments are compared with the calculated values of ACI code. It was found ACI calculated values remain conservative in strength 10MPa and 15MPa, but in the 5MPa calculated values is very close to experiment results.So,the formula of ACI code used in low strength concrete may not be conservative. From the experiments of this study,it was also found a new failure mode as steel bending failure. Finally, the importance of the shear strength of the interface between the post-installed rebar and concrete was addressed with an actual experiment of RC shear wall and the results of the reconnaissance of earthquake disaster in Taiwan.
標題震害橋梁載重試驗之分析
作者陳俊仲、宋裕祺、張峰愷、邱毅宗、李政寬、許家銓、葉芳耀、黃炳勳、陳嘉盈、吳萬龍
關鍵字遺傳演算法、反應曲面法、車載試驗
摘要本文以震害橋梁載重試驗為研究分析案例，採用有限元素分析軟體建構橋梁結構模型，並依車輛載重現地試驗量測成果，瞭解橋梁於試驗現況之結構基本特性，用以回饋分析模型設定參數調校參考，目的為確保建構之結構分析模型可詳實反映真實橋梁基本結構特性與輸出反應。由於建置可靠之結構分析模型，考量各受載情境下推估結構可能的真實反應，是訂定橋梁長期監測與管養量化參數主要應用參考方法，惟真實橋梁結構構件與系統複雜度高，欲完整詳實模擬真實橋梁結構，通常可利用現地橋梁試驗量測得真實結構反應，並據以適當調校結構分析模型參數，讓分析模型反應接近真實結構反應。一般而言必須採用足夠多的分析元素才能得到較具代表性的結構分析模型，因此在調校模型參數過程配合反覆演算需求，經常遇到調校過程分析效率不佳或無法完成模型參數調校目的。因此本研究應用實驗設計方法，建立反應曲面函數以代表原有限元素分析模型，並針對反應曲面函數參數，配合遺傳演算法進行分析模型選定之設定參數最佳化，透過最佳化後之反應曲面函數，取得最佳之分析模型材料設定參數。本研究方法可有效提升結構分析模型參數調校之效率，提高分析模型相對真實結構之代表性，近而將分析模型應用於結構長期監測與健康診斷系統之安全資訊評估。
TitleLoading Test Analysis of An Earthquake-Damaged Bridge
AuthorChun-Chung Chen, Yu-Chi Sung, Zheng-Kuan Lee, Chia-Chung Hsu, Fang-Yao Yeh, Yu-Chi Sung, Feng-Kai Chang, Yi-Tsung Chiu, Ping-Hsun Huang, Jia-Ying Chen, Wan-Long Wu
KeywordsGene Algorithm, Response Surface Method, Loading Test
AbstractThis paper conducts an analysis on loading tests of the earthquake-damaged bridge. The study uses the commercial finite element program to build a bridge analytical model, and the analysis result is compared with that of the field load testing to verify the proposed model. Generally, in order to improve the reliability of the finite element model, it is needed to adjust some modeling parameters using field experimental data to realize the representative characteristic of the bridge structure. However, the structural model usually involves numerous elements which lead the poor analysis efficiency of modeling parameters adjustment work. In view of this, this study applies the response method of experimental design function to take place of the finite element model by statistical experimental design theory and integrates the genetic algorithm to optimize modeling parameters which were used in the model and can make the model gives the reliable results which close to static and dynamic characteristics of the actual bridge.
標題鋼筋混凝土建築物耐震能力初步評估系統PSERCB之建置與應用
作者宋裕祺、蔡益超、陳建忠、賴明俊、邱毅宗、陳俊榕、林宏軒、陳長佑、顏志良
關鍵字雲端作業系統、定量評估、防災
摘要老舊建築物或因設計年代久遠或因現況不佳等因素，其耐震能力恐未能符合現行規範標準。若逐一進行詳細耐震能力評估，將耗費相當龐大的經費與時間。本文根據內政部建築研究所2014 年委託研究計畫所制定的新版建築物耐震能力初步評估方法為基礎，開發出鋼筋混凝土建築物耐震能力初步評估系統(Preliminary Seismic Evaluation of RC Building, PSERCB)，讓使用者能夠快速且不失準確的估算建築物的耐震能力。PSERCB 能夠將耐震能力初步評估結果以定性與定量方式呈現，並以分數表示，讓評估者能夠判別建築物耐震能力之情況，作為後續是否須執行耐震詳細評估與補強或者是拆除重建之參考依據。本系統採雲端作業方式，評估者之調查資料將儲存於雲端資料庫內，可提供各級政府資料檢視、分析、統計與管理之用，並可作為擬訂防災策略所需大數據(Big Data)分析之依據，達到災害控管的目的。
TitleStudy and Establishment for Cloud Platform of Preliminary Seismic Evaluation of Reinforced Concrete Buildings
AuthorYu-Chi Sung, Ming-Chun Lai, Yi-Tsung Chiu, Chun-Jung Chen, Hong-Syuan Lin, Chih-Liang Yen, I-Chau Tsai, Chien-Jung Chen, Chang-Yu Chen
KeywordsCloud Operation System, Quantitative Evaluation, Disaster Prevention
AbstractThe numerous existing buildings maynot behave qualified seismic performance satisfied with the current seismic design code as a result of material deterioration or outdated design, etc. It needs a significant cost and time to do the detailed seismic evaluation of existing buildings for determination on necessary seismic retrofit. Therefore, development of a preliminary seismic evaluation system giving a rapid and reliable result is very important currently in Taiwan. This paper focused on developing the preliminary seismic evaluation of reinforced concrete buildings (PSERCB), based on research of Profs. Tsai and Sung 2014, granted by Architect Research Institute, Taiwan. Both qualitative and quantitative evaluation results are involved in this framework. A cloud platform was established for the engineers to input the inspection of current status of buildings and the evaluation report is able to be downloaded as technical report. All the data on the cloud platform are collected as the basis of big data analysis for strategy of disaster prevention to government in the future.
標題立面不規則建築受震反應簡化分析方法
作者曹智嘉、林瑞良、蔡克銓
關鍵字立面不規則建築、退縮、非線性反應歷時分析、振態側推分析、振態反應歷時分析
摘要耐震規範中對立面不規則建築有其定義與限制，並且要求須以動力分析方法進行結構設計。除了以有限元素分析法(finite element method, FEM)進行全結構的非彈性動力分析外，振態側推分析法(modal pushover analysis method)是常用的簡化分析方法之一。進行振態側推分析可以得到各振態的非彈性受力與變形關係，由此受力與變形關係可以建立代表該振態的單自由度振態系統。再進行各單自由度振態系統的非線性反應歷時分析，並將各振態造成的反應歷時相加，即可求得結構的總反應，在本研究中稱此簡化分析方法為單自由度振態分析方法(single-degree-of-freedom modal analysis method,SDM)。相關文獻顯示SDM會高估底層或下半結構較強或較強且較硬之立面不規則建築之下部樓層的受震反應，建議對此類結構仍應採用較為複雜與耗時的FEM來分析其受震反應。然而此類型之立面不規則結構物常見於實際工程中，若能發展適合的簡化分析方法，則將有助於工程的應用。有鑒於單自由度振態系統無法反映上述類型結構上下兩部分顯著不同的受震反應， 本研究提出二自由度振態分析方法(two-degree-of-freedom modal analysis method,2DM)，將每個振態系統以兩個自由度分別代表上部及下部結構的振態反應，經由疊加各振態所造成的反應歷時以估算結構的總反應歷時。本研究以一棟9層樓及一棟20層樓規則平面抗彎矩構架做為原型建築，修改每一個原型建築成為四個立面不規則構架(底層較強、底層較強且較硬、下半結構較強、下半結構較強且較硬)做為研究之標的建築。以FEM、SDM及2DM分析上述八個立面不規則構架分別受到60筆地震記錄作用下的反應。本研究顯示當結構保持彈性，2DM與SDM分析結果完全相同；當結構進入非彈性，一般而言2DM估算的各樓層反應較SDM準確，能夠有效降低被SDM高估的下部結構的最大層間位移比。
TitleA Simplified Seismic Analysis Procedure for Vertically Irregular Buildings
AuthorChih-Chia Tsaur, Jui-Liang Lin, Keh-Chyuan Tsai
Keywordsvertically irregular building, setbacks, nonlinear response history analysis, modal pushover analysis, modal response history analysis
AbstractMost seismic building design codes describe the features of vertically irregular buildings. In addition, these building design codes prescribe that dynamic analysis should be adopted in the seismic analysis and design of these irregular structures. Besides the finite element method (FEM), which performs inelastic dynamic analysis to complete finite element models, the modal pushover analysis (MPA) method is one of common simplified seismic analysis procedures. The force-deformation relationship of each vibration mode obtained from the MPA method is employed to construct the corresponding single-degree-of-freedom (SDOF) modal system. The modal response histories are obtained from performing nonlinear response history analysis to each SDOF modal system. The total seismic responses of the building are estimated by adding up the seismic response histories resulting from all vibration modes. This study designates the aforementioned simplified method as the single-degree-of-freedom modal analysis method (SDM). Some research literatures showed that using SDM leads to overestimated seismic responses of the lower parts of the vertically irregular buildings, which have stronger or stronger-and-stiffer bottom story or lower half. Instead of the SDM, the complicated and time-consuming FEM was thus suggested for the seismic analysis of this type of buildings. Nevertheless, this type of vertically irregular buildings is common. It would benefit engineering practice if there are simplified seismic analysis methods available to this type of irregular buildings. In light of the incompetence of using the SDOF modal systems to simultaneously reflect the seismic responses of the super- and sub-structures of the buildings, this study proposes the two-degree-of-freedom modal analysis method (2DM). 2DM is basically the same as SDM, except that 2DM represents each vibration mode as a two-degree-of-freedom modal system. One 9-story and one 20-story regular moment resisting frames are selected as the prototype building in this study. Each of the two prototype buildings are further varied into four vertically irregular buildings as the target buildings. The four variations include buildings with stronger, stronger-and-stiffer first story; stronger, stronger-and-stiffer lower half. FEM, SDM, and 2DM are applied to the eight target buildings subjected to the selected 60 ground motions. This study shows that the analysis results obtained from 2DM are the same as those obtained from SDM as long as the structures remain elastic. While the structures become inelastic, 2DM generally results in more accurate estimations of inter-story drifts, compared with those obtained from SDM. The overestimated peak inter-story drifts of the substructures by using SDM are effectively reduced by using 2DM.
標題高層建築於干擾效應下氣動力及氣彈力實驗結果比較
作者羅元隆、陳紀柔
關鍵字高層建築、氣彈實驗、干擾效應、干擾因子
摘要風力對高層建築物的反應為高層建築物設計中重要的一環，本研究以建築物之間風力所造成的干擾效應影響比較為主要探討項目，比較氣動力實驗與氣彈力實驗結果在干擾效應影響下的差異性。實驗結果討論分為三個部分，第一部分為探討干擾效應下氣動力實驗─風壓量測法之建物整體平均風力係數、擾動風力係數與風力干擾因子；第二部分為探討干擾效應下氣彈力實驗─位移量測法之位移擾動值與位移干擾因子；第三部分為比較第一部分與第二部分之相同流場下不同實驗方法之干擾效應結果差異。在不同的實驗方法中所得到的結構擾動反應值之變化與不同干擾位置之影響甚大。且由氣彈力實驗結果中找出氣動力實驗無法預估的結構氣彈力現象。本研究期望能藉由兩種實驗方式指出結構物受干擾效應影響下可能發生的遮蔽效應及增幅效應隨著干擾位置變動，而有不同的結果。
TitleInterference Effects on High-rise Building Based on Aerodynamic and Aeroelastic Tests
AuthorYuan-Lung Lo, Chi-Rou Chen
KeywordsHigh-rise building, Aero-elastic test, Interference effect, Interference factor
AbstractWind effects on high-rise buildings are one of the most important topics in safety designs of structures, especially the target building is neighbored by another or even multiple high-rise buildings. This study intends to compare the differences between the results from the aerodynamic test and the results from the aeroelastic test. Physical scaling tests are planned in three parts: firstly the aerodynamic test is conducted in order to understand mean and fluctuating force coefficients of a square prism model with interference effects; secondly the aeroelastic test is conducted in order to examine the displacement variation under various velocities and terrain flows; thirdly the results from both tests are compared to find the differences by means of displacement estimation methodologies. It is found that, adopting the aerodynamic test for wind-induced response is not reliable compared to the aeroelastic test since the wind-induced response with/without interference effects are much more complicated and need more investigations in systematic aeroelastic test works.